Efficient multi-Watt continuous-wave (CW) yellow emission at 586.5 nm is demonstrated through intracavity frequency-doubling of a Nd:GdVO₄ self-Raman laser pumped at 880 nm. 2.51 W of CW yellow emission with an overall diode-to-yellow conversion efficiency of 12.2% is achieved through the use of a 20 mm long Nd:GdVO₄ self-Raman crystal and an intracavity mirror which facilitates collection of yellow emission generated within the resonator, and reduces thermal loading of the laser crystal.

The unique properties of optical vortex beams, in particular their spiral wavefront, have resulted in the emergence of a wide range of unique applications for this type of laser output. These applications include optical tweezing, free space optical communications, microfabrication, environmental optics, and astrophysics. However, much like the laser in its infancy, the adaptation of this type of laser output requires a diversity of wavelengths. We report on recent progress on development of optical vortex laser sources and in particular, focus on their wavelength extension, where nonlinear optical processes have been used to generate vortex laser beams with wavelengths which span the ultraviolet to infrared. We show that nonlinear optical conversion can be used to not only diversify the output wavelength of these sources, but can be used to uniquely engineer the wavefront and spatial properties of the laser output.

We report a continuous-wave Nd:GdVO₄ self-Raman laser generating wavelength-selectable output in the green-yellow spectral region. The laser combines stimulated Raman scattering (SRS) with intracavity second harmonic and sum-frequency generation (SHG/SFG) to enable “on-demand” operation at any one of three wavelengths, 532 nm, 559 nm and 586 nm, each with output power greater than 3.5 W. Using experimental and numerical modelling results, we show how the highly-interactive, simultaneous non-linear processes of SRS and SHG/SFG may be balanced to achieve stable, selectable multi-wavelength visible operation.

We demonstrate the direct generation of a first-order LG₀₁ Laguerre Gaussian (vortex) mode operating at the first-Stokes wavelength of a diode end-pumped, Nd:GdVO₄ self-Raman laser. To the best of our knowledge, this is the first report of intracavity stimulated Raman scattering (SRS) being used as a method for frequency conversion of a vortex laser beam and it is effective in enabling the frequency-converted (Stokes) beam to have the same LG₀₁ mode as the fundamental beam.

We report the generation of multi-watt continuous-wave (CW) yellow laser emission from an intracavity diode-pumped Nd:GdVO₄ /BaWO₄ Raman laser utilising a high-Q resonator (for fundamental and first-Stokes wavelengths) and intracavity frequency-doubling in LBO. CW output power of 2.9 W is achieved with a high overall diode-to-yellow conversion efficiency of 11% and with good beam quality (M²~2.5).

Optics InfoBase is the Optical Society's online library for flagship journals, partnered and copublished journals, and recent proceedings from OSA conferences.